Meteorite trail near Chelyabinsk, Russia

[Mick]

NASA asteroid expert Don Yeomans, head of the agency's Near-Earth Object Program Office, told SPACE.com that the object which exploded over a thinly inhabited stretch of eastern Europe today was most likely an exploding fireball known as a bolide.
More than 500 people were injured, mostly by glass cuts when windows shattered during the blast, according to the Russian Emergency Ministry.
"If the reports of ground damage can be verified, it might suggest an object whose original size was several meters in extent before entering the atmosphere, fragmenting and exploding due to the unequal pressure on the leading side vs the trailing side (it pancaked and exploded),"

The question then is if the "explosion" caused the shock wave, or if it was just the sonic boom. And how many megatons was the explosion? And how long did it take?

The Space Shuttle used to fly in here over Los Angeles sometimes. There was a sonic boom, and the windows rattled, even set off car alarms. Check out this video at 2:59:



Or this one at 1:00


Space Shuttle:
Speed = 17,000 mph
Mass = 500,000 pounds
Kinetic Energy = 6.5 * 10^12

Meteor
Speed = 40,000 mph
Mass = 20,000,000 pounds
Kinetic Energy = 1.5 * 10^15 (1500 * 10^12)

So the Meteor had 230x the kinetic energy of the space shuttle. It seems reasonable that it would have a much larger sonic boom. If the space shuttle can rattle windows, then something with 230x the amount of energy can break windows.

[Mick]

And here's an example of a sonic boom breaking windows. It's vastly smaller and slower, but as it's low it's more effective:



You might have to watch it a couple of times, look at the windows in the building after the camera swings around.



http://theaviationist.com/2012/07/02.../#.USMVYVpBcZw

Content from external source:


On Jul. 1, 2012, at around 10:20 local time, the windows of the Supreme Court and Congressional buildings in Brasíla, Brazil’s capital, were shattered as two Mirage 2000 fighter jet performed a flyover during the ceremony of exchange of the national flag at the Praça dos Três Poderes, at the Esplanada dos Ministerios.
Although nobody was injured the fighter flew so low and fast that the shock wave they generated broke almost all the windows of Supreme Court glass facade.
In a statement, Brig Ar Kanitz Marcelo Damasceno, chief of the Center for Social Communication of the Força Aérea Brasileira (FAB), said that the Brazilian Air Force Command has initiated the investigation of the incident and will compensate the damage caused.

[RolandD]

The question then is if the "explosion" caused the shock wave, or if it was just the sonic boom. And how many megatons was the explosion? And how long did it take?

I have to say, when I post that up there I was sure that the meteor had exploded. Now, I still think that it did, but not with nearly as much confidence. I thought that it would be easy to prove my point. It's not. I'd say that both are potentially correct.

[HappyMonday]

Internet paranoids are using the interest in the Russian incident to raise awareness with their flock of this -

http://www.space.com/6829-military-h...lassified.html

...by reblogging it like this -

http://wewillblowyourmind.blogspot.c...ball-info.html

[scombrid]

I've heard the space shuttle double sonic boom and it really shakes the building.

The meteor blowing up was probably much like over heated pyrex cookware blowing up when you open the oven and cool air rushes in. It shatters pretty violently. Meteor is quite cold when incoming but heats super fast. When you shatter something as hot as an incoming meteor it should definitely glow very brightly as all the bits burn. But the bulk of the damaging shockwave likely was generate by the sonic boom.

[Jay Reynolds]

This from the American Meteor Society contains several videos showing the fairly large time after formation of the trail that the sonic boom reached the town, and the secondary sonic booms from fragments, as well as some expert opinions.
http://www.amsmeteors.org/2013/02/la...l-hits-russia/

[PCWilliams]

[RolandD]

I just got around to reading the May 2013 issue of Popular Mechanics and found this on page 13:

Content from external source:

Explosive Ablation...(snip)...When an asteroid approaches Earth at 40,000 mph, the shock wave it causes when hitting the atmosphere strips, or ablates, melted material from its surface. As the meteor falls, its rocky center becomes a hot vapor that expands so quickly it causes an explosion.

Sorry I couldn't find a link on the web.